Hello
yes, every bubble has this issue. This issue starts recently, and only exists when using ppa:xorg-edgers/ppa, both intel and nvidia video card of mine have this issue, and no matter what driver(nouveau/nvidia)
my window-manager is gnome.
i donno this is in fact an issue of xorg 1.9 and/or notify itself?

Thanks for the report, this is most likely an issue with the pixman version in the PPA. The packages in that PPA are in heavy flux and are known to be unstable, and reports on launchpad against the Ubuntu packages aren't really appropriate unless the issues exist in the Ubuntu packages as well where stable versions are shipped. If you can reproduce this on stock maverick please reopen this bug, and if you want to remove the PPA there are instructions in the description of xorg-edgers. sudo apt-get install ppa-purge && sudo ppa-purge xorg-edgers will do it.